The present invention relates to an acidified imitation cheese composition having a good shelf life, having good mouthfeel and taste, which can be manufactured into imitation hard, soft, or semi-soft cheeses and safely packaged using virtually any commercial packaging system, including hotfill, retort, or aseptic systems. The acidified imitation cheese composition of the invention can be used to make an assortment of imitation cheese products, including, but not limited to, imitation cheese loaves, logs and balls, imitation cheese sheets, imitation cheese wheels, imitation cheese slices, and imitation grated and shredded cheeses in a variety of flavors and colors.
Pasteurized process cheese products have been on the market for many years and are usually sold as shelf stable products. These products, such as the cheese slices used in the cheeseburgers of most American fast food restaurants, are favored by consumers and food service providers alike because of their versatility, shelf stability, and lower cost in comparison to natural cheese products. Pasteurized process cheese products typically have a relatively high pH (about 5.4 to 6.0) and a moisture content of approximately 50%. Because of their high pH, pasteurized process cheeses products fall into the category of “low acid food products” as defined in 21 C.F.R. § 114.3(d) (foods having a pH of greater than 4.6). It is well known in the industry that low acid products can easily become spoiled by microbial growth, thereby creating an unpleasant and potentially dangerous culinary experience for the consumer if handled or packaged improperly. To reduce the ever-present danger of microbial growth in low acid foods, in particular, contamination by Clostridium botulinum, the food industry has developed various methods of preservation applicable to low acid foods. Many low acid products are preserved by application of a high-temperature thermal treatment, such as sterilization, to a finished product, thereby destroying any viable bacterial contaminants. Commonly used food manufacturing procedures, such as aseptic and retort processing, incorporate these high heat treatments.
While effectively enhancing food safety, food sterilization through thermal processes has some inherent drawbacks. Both aseptic processing and retort processing require heating the finished product to high temperatures (around 121° C.-148° C. or 250° F.-300° F.) to accomplish sterilization. In addition to increased energy and equipment expenditures, high temperature processing can result in what is referred to as “burn on,” linescale, or fouling of the product, where a commercially unacceptable burned or overcooked taste is imparted. Fouled product is unsaleable and is therefore discarded, resulting in a waste of materials and labor. Accordingly, the productivity and profitability of the manufacturing process is decreased.
Additionally, thermally sterilized food products must be retained by the manufacturer, by law, for an incubation period before releasing the product to the consumer. The finished product must be held in incubation for a minimum of approximately ten days before shipping, in order to verify that the sterilization process was adequate.
As an alternative to thermal sterilization, shelf stability can be achieved in some types of low acid products by control of the nature and amount of the various components which make up the substance of the food product. Preservatives may be added to the product, or bacterial growth may be controlled by limitations on the water activity (aw) of the product's composition. However, these preservation methods have drawbacks which limit their practical applicability in large scale production and distribution situations. For example, foods containing large quantities of preservatives are disfavored by consumers, and enhanced shelf stability through control of water activity is feasible in only a narrow range of product types, because of the limitations placed on the composition of the product itself.
In the case of pasteurized process cheese products, bacterial stability is most often achieved though use of what is known in the art as “hurdle technology,” a combined effect of carefully restricted levels of pH, moisture (water activity aw), and salts (emulsifier phosphates and NaCl) in the process cheese composition, which is generally accepted in this field. Hurdle technology and its applications in the area of food preservation are well known and documented in the art, e.g., Tanaka, J. Food Protect., vol. 49, no. 7, pp. 526-531 (July 1986), the contents of which are incorporated herein by reference.
The hurdle technology food preservation model predicts the level of bacterial stability of a given composition, depending on the specific levels of each the four parameters (“hurdles”) of pH, moisture, emulsifier phosphates, and NaCl present in the composition. However, because the effects of variations or deviations from any of the prescribed parameters are unpredictably synergistic, the hurdle predictive models have created a paradigm of the specific component levels. Therefore, production-scale hurdle manufacture is limited to a narrow range of permutations of each of the parameters, and is limited to a relatively low level of moisture in the product (58% moisture by weight, or less), in order to ensure proper preservation of the resultant food product.
In contrast to low acid foods, including pasteurized process cheeses, “acidified” foods, as defined in 21 C.F.R. § 113.4(a), do not require application of any of the preservation techniques discussed above. Because such products are less susceptible to microbial spoilage by virtue of their acidic pH, they can be formulated for taste, texture, and cost advantage without regard to the effects of high heat sterilization or parameters of moisture or other “hurdles.”
Significantly, an acidified cheese-type product could be formulated without regard to the moisture parameter required by the hurdle processing of pasteurized process cheese. Thus, the overall moisture content of the cheese-type product could be drastically increased, thereby conferring a significant economic advantage upon the manufacturer, who may replace the costly solids components with less expensive water or moisture components, while maintaining food safety. In addition, freedom from the hurdle processing parameters would allow manufacturers more flexibility to produce the lower salt and/or lower fat cheese-type products containing non-traditional emulsifiers, for which there is a growing market demand, without sacrificing consideration of the safety of the cheese-type product.
Consequently, because of the safety, regulatory, and manufacturing advantages of high acid or “acidified” food products, an imitation cheese composition which retains the flavor, texture and consistency properties of conventional pasteurized process cheese manufactured using hurdle technology would be particularly desirable. Such an acidified imitation cheese composition would have the benefit of being safer than conventional pasteurized process cheeses preserved by hurdle technology and/or sterilization because the acidic pH is sufficient to retard the growth of microbial pathogens. In addition, processing costs would be less for an acidified imitation cheese composition, as no sterilization would be required, nor would adherence to the hurdle predictive models, thereby reducing utility costs and increasing productivity by eliminating fouling and spoilage resulting from errors in manufacturing.
In the past, attempts have been made to develop an acidified cheese-type product which could occupy the same market niche as pasteurized process cheese. However, these products fail to adequately mimic the flavor, texture, and consistency of conventional pasteurized process cheeses. Significantly, unlike the savory, cheesy flavors characteristic of conventional pasteurized process cheese, the acidified cheese-type products of the prior art have been characterized by unpleasant, sharp, tart, sour or acidic flavors. As a result, these products have been commercially unacceptable without the addition of flavor-imparting substances, such as tomatoes, onions, peppers, and smoke flavors, to mask the unacceptable tastes.
U.S. Pat. No. 4,143,175 to Whelan et al. (“Whelan '175”) discloses a cheese food product for use in a shelf stable pizza sauce with a moisture of up to 70%, a pH of less than 4.6 and between about 57% and 63% natural cheese. This product would be significantly more expensive to produce due to the high natural cheese content than the present invention.
U.S. Pat. No. 4,089,981 to Richardson (“Richardson '981”) discloses a fibrous simulated food product, wherein the pH is less than 4.6 and is generated with a low volume of acid. However, Richardson '981 discloses an imitation cheese product with moisture of only about 56%, and protein of about 6% and between 10% and 85% cellulose fiber. Unlike the present invention, this type of product would likely not provide the consistency desired for cheese or the additional advantages of lower manufacturing costs based on the use of a high moisture content along with a lower protein content.
U.S. Pat. No. 4,031,254 to Kasik et al. (“Kasik '254”) discloses a dry composition to which water is added to make cheese sauces and similar compositions. Even with the added water, the total moisture content is below 55% and the protein content is high. This does not offer the savings in manufacturing costs by using a higher moisture content and a lower protein content. The high protein content also may create a need for a higher amount of an acidulent in order to lower the pH, which would cause a sour acidic taste, similar to the known prior art.
U.S. Pat. No. 4,684,533 to Kratochvil (“Kratochvil '533”) discloses an imitation cheese product having a protein content of at least 1.5%, but with a pH not below 4.6.
U.S. Pat. No. 5,009,867 to Kratochvil (“Kratochvil '867”) discloses cheese-type products with high natural cheese contents.
U.S. Pat. No. 4,608,265 to Zwiercan et al. (“Zwiercan '265”) and U.S. Pat. No. 4,937,091 to Zallie et al. (“Zallie '091”) both disclose an imitation cheese, wherein up to 100% of the caseinate is replaced with starch. This results in a high starch, low protein imitation cheese. However, a high starch imitation cheese product of this type would likely have poor taste and textural characteristics. Additionally, in contrast to the present invention, it appears that this type of product relies on hurdle technology for shelf stability, based on its high solid, low moisture content.
Consequently, there remains a need in the food industry for an acidified composition useful in the manufacture of imitation cheese, including imitation cheese loaves, logs and balls, grated and shredded imitation cheeses, and imitation cheese wheels, which possesses a flavor, texture, and consistency as good as or superior to conventional pasteurized process cheese, yet, by virtue of its acidic pH, is resistant to microbial growth and less expensive to produce.